Various manufacturing methods of a composite molded body integrating an FRP base material and another molded body, in particular, another thermoplastic resin molded body, are known. For example, JP 2012-153069 A discloses a method of temporarily forming a carbon fiber reinforced resin (CFRP) sheet-like base material outside a mold, inserting it into the mold to form by high-speed heating and cooling, inserting the formed body into a mold and injecting a resin into the mold to obtain a composite molded body. In that method, however, since at least the temporary forming is performed outside a mold, it is not a process capable of compositing in a same mold, and the molding process becomes complicated.
Further, JP 2013-252644 A discloses a method of fixing a CFRP base material in an injection mold and compositing by injecting a resin. However, there is only a description of a simple layered composite molded body and, in particular, a method of forming a CFRP base material having a three-dimensional shape is not mentioned.
Further, JP HEI 5-185466 A discloses a manufacturing method of a composite molded body in which a CFRP is stamping molded in a mold, the mold is backed to form a space, and a resin is injected into the same mold. However, although that method is suitable for molding a random fiber base material in which reinforcing fibers are randomly arranged, preheating for stamping molding is necessary and, for example, in molding a continuous fiber base material, a problem occurs in which the fibers are broken or their orientation is disturbed, and when a plurality of base materials are to be laminated, or a base material is to be laminated at a predetermined position, a CFRP flows together with a resin at the time of injection and, therefore, there is a problem that it is difficult to laminate the CFRP accurately at a desired position of a molded article.
Furthermore, JP 2011-143559 A discloses a method of manufacturing a composite molded body by thermally welding an injection molded article and a CFRP base material in a molding machine. In that method, however, since the CFRP base material is laminated by laser welding, press molding or the like after manufacturing the injection molded article, especially it is difficult to laminate the CFRP base material to a three-dimensional shape portion of the injection molded article.
It could accordingly be helpful to provide a method capable of manufacturing a composite molded body having a targeted three-dimensional shape portion efficiently by, in particular, in a same mold, forming a tape-like FRP base material into a three-dimensional shape and integrating it with a thermoplastic resin with a high joining strength and a high accuracy.
Further, it could be helpful to provide a manufacturing method of a composite molded body partially added with special measures to a thermoplastic resin joined and integrated as described above to enable maintaining a desired integrated shape or integrated formation during or after the molding.